But what if Ashby had survived even with his "issues" and had also been at Gettysburg helping out Stuart or helping out Lee while Stuart was on his side exploit? Lee needed "eyes and ears" and maybe Ashby could have provided them while Stuart captured a lengthy wagon train, etc.

Interesting Cleburnefan, but what if Stuart had been killed leading Jacksons Corps at Chancellorsville? Wade Hampton in command of Conf. cavalry leading up to and during Gettysburg (if the battle would have ended up in Gettysburg that is)? Wade Hampton was every bit the cavalry commander Stuart was without the "flair". Doubtfull Hampton would have engaged in such an enterprise as Stuart got caught up in.